Coffee maker



May 8, 1951 M. H. GRAHAM 2,552,169

COFFEE MAKER Filed Aug. 28, 1944 7 Sheets-Sheet l Suma/who@ MAUR/'0E H.GRAHAM m www@ M. H. GRAHAM May 8, 1951 'COFFEE MAKER 7 Sheets-Sheet 2Filed Aug. 28, 1944 FIG.2

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MAUR/0E H. GRA HAM May 8, 1951 M. H. GRAHAM 2,552,169

COFFEE MAKER Filed Aug. 28, 1944 7 Shees-Sheet 5 f MAUR/0E H. GRAHAM@4461,94

M. H. GRAHAM COFFEE MAKER May 8, 1951 7 Sheets-Sheet 4 Filed Aug. 28,1944 lOl m mm NH WA WR G. H. E m. R U A M M. H. GRAHAM May 8, 1951COFFEE MAKER 7 Sheets-Sheet 6 Filed Aug. 28, 1944 MAURICE H. GRAHAM BY.pa/Vga# Arrrs.

M. H. GRAHAM May 8, 1951 COFFEE MAKER '7 Sheets-Sheet 7 Filed Aug. 28,1944 MAURICE H. GRAHAM PUSH |N TO START MOTOR BY Arrvs.

Patented May 8, 19,51

UNITED STATES PATENT OFFICE COFFEE MAKER Maurice H. Graham, St. LouisPark, Minn.

Application August 28, 1944, Serial No. 551,507

15 Claims.

This invention relates to coffee makers, and directed to improvedmechanism for circulating and infusing the coifee making liquid.

The general object of the invention is to provide a coffee maker inwhich coffee making liquid is circulated through the coffee grounds at arelatively high flow velocity and in such manner as to provide a moreefficient extraction.

The invention contemplates a novel and improved coffee holding infusionunit in which the liquid passes upwardly, instead of downwardly, throughthe bed of coffee grounds and delivered to a storage chamber from theupper end of the unit.

The invention further contemplates improved power driven pumpingmechanism for circulating the liquid through the coffee. Such mechanismcombines the advantages of high circulation pumping capacity with anarrangement of the pump and pump driving mechanism which avoids thenumerous disadvantages of prior power driven pump coffee makers.

As in my prior pending application, Serial No. 438,029, filed April '7,1942, now Patent No. 2,356,784, granted August 29, 1944, of which thepresent application is a continuation-in-part, the power driven pumpmechanism includes a pump located within the coffee maker which isdriven magnetically from an exterior power source and without thenecessity of extending a shaft or other positive drive coupling into thecoffee maker. While the present magnetically driven pump mechanism isgenerally similar to that in such prior application, the same isSubstantially more eflicient in circulating capacity despite the verycompact lightweight design which is very desirable for a coffee maker.

As will hereafter become apparent, the invention is applicable to coffeemakers constructed both of metal and glass. Further, electric heatingunits may be permanently associated with a coffee maker embodying theinvention, or an electric heating unit may be employed in a base stovefrom which the coffee maker is removable. Automatic control means maybe, and preferably are, provided to control both the pumping mechanismand the heating mechanism to the end that the invention provide a fullyautomatic coffee maker.

The above and other objects and features of the invention will be morefully understood by reference to the embodiments shown in theaccompanying drawings.

In such drawings:

Fig. 1 is a sectional elevation of a coffee maker according to theinvention;

Fig. 2 is a cross-section taken at line 2-2 of Fig. 1 showing certaindetails of the pump power unit and control mechanism;

Fig. 3 is a cross-section taken at line 3--3 of Fig. 1;

Fig. 4 is a further cross-section taken at line Li-ll of Fig. 1; A

Fig. 5 is an expanded perspective view of the disassembled parts of theliquid circulating mechanism;

Fig. 6 is an enlarged fragmentary vertical section taken at line 6 6 ofFig. 2 showing details of a control switch;

Fig. 7 is a fragmentary vertical section showing details of thethermostatic control;

Fig. 8 is a plan view of the motor rotor for driving the pump mechanism;

Fig. 9 is a diagrammatic view of the control circuit;

Fig. 10 is a perspective vievv of a further embodiment of coffee makerembodying the invention;

Fig. 11 is a vertical section of the same coffee maker taken at the linelI-Il of Fig. 10;

Fig. 12 is a perspective expanded view, partly in section, of the mainparts of the pumping, circulating and infusing mechanism;

Fig. 13 is a perspective enlarged View of the pump and motor rotors;

Fig. 14 is a perspective view of the underside of the pump assembly;

Fig. l5 is a diagrammatic view of the control circuit for the coffeemaker of Fig. 10;

Fig. 16 is a vertical section of a third embodiment of the inventionwherein the coffee maker is constructed of glass and detachablyassociated with an electric stove base;

Fig. 17 is a fragmentary sectional elevation taken at right angles toFig. 16;

Fig. 18 is a perspective view of the thermostatic switch with the casingremoved;

Fig. 19 is a corresponding perspective View of the thermostatic switchcasing;

Fig. 20 is a perspective view of a further control switch; and,

Fig. 21 is a diagrammatic view of the wiring circuit employed with thecoffee maker of Fig. 16.

Fig. 22 is a top plan view of the motor stator.

The coffee maker shown in Figs. 1 to 9 includes a metal pot 3E!upstanding from an integral hollow base 3| and having a liquid storagechamber 32 in its lower portion. The bottom portion 33 of the vessel isof reduced cross-section and surrounded by an electric heating coil 34.Projecting from the base portion 33 is a relatively small well 35 inwhich is removably fitted a small housing 36 having specially formedthreaded cap 3l.

A removable cup 38 depends from a shoulder in housing 36 to form a pumpchamber 39. An inlet port 48 located centrally of cap 37 conducts liquidfrom storage reservoir 32 to pump chamber 36. Journalled in the bottomof housing 36 and extending upwardly therethrough is a rotatable shaftlil. chamber 39 is a rotary bladed pump member 42.

Fixed to such shaft in pumpv 3 As best shown in Figs. 1 and 5, housingcap 31 is of hollow circular cross-section and fitted with an insertdefining liquid inlet port il@ and having a flange 43 of ovalcross-section. Such flange forms with the cap a liquid outlet chamber towhich liquid is pumped from the pump chamber through the diametricallyopposite openings between the flange and the cap wall.

Upstanding from cap 31 and communicating with pump discharge chamber 45are a pair of conduits et and l which merge at union 58 from whichextends upwardly a. further single conduit f4.9. It will be seen thathousing 36, the pump mechanism and conduits lit, il and i9 constituteasingle unit which is removable as such from the vessel.

Supported in the upper portion of vessel 3f) removably on conduit L39 byange 5@ is a coiee holding infusion unit 5E. Whereas conventional coffeeholders have perforate walls and liquid enters the upper end thereof andflows downwardly through the coffee grounds and out through the wallperforations, the present coffee holder El has imperforate bottom andside walls. Mounted in the lower portion of holder 5i in spacedrela-tion to the bottom wall 52 is a perforate disc 52 which provides asupport for the bed of coffee grounds. Such disc is removably mounted onthe upper portion of conduit it by a thimble 53. Formed between bottom52 and disc 52 is a liquid entrance chamber Ti to which liquid isdelivered from tube le through a series of ports 5d. The liquid is thusable to penetrate throughout the entire width of holder 5i so as to bepumped upwardly throughout the entire area of the bed of coffee grounds.After being in fused the liquid is discharged from holder 5l at a pointsomewhat above the level of the bed of coffee grounds. While a series ofdischarge openings may be provided in the side of holder u El near thetop thereof, is preferred to make the side wall imperforate throughoutits height and to provide the upper end of the holder with a secondperforate disc detachably mounted by a. securing element 55 on theclosed upper end of conduit dil and knob 57 fixed to the center of suchdisc.

Through the mechanism just described it will be. understood that liquidfrom storage chamber 32 is repeatedly circulated by the pump mechanismupwardly through conduits llt, il and it into the lower portion of thecoffee holding infusion unit 5i, enters the infusion unit below thecoffee bed, flows upwardly through disc 52' and the bed of coffeegrounds, thence upwardly through top disc 55 and then discharges overthe top edge of the unit and thence back to storage chamber 32. The pumpmechanism is capable of delivering liquid in a steady stream of fairlyhigh velocity so that liquid flows upwardly through the infusion unit inconsiderable volume. The coffee grounds, instead of packing down andtending to escape into the storage reservoir as in the case ofconventional infusion units is buoyed up' by the upwardly owing liquid.Because the grounds are thus more widely distributed in the unit agreater degree of contact with the liquid is possible and a moreeflcient extraction is obtained. Disc 55 serves to prevent escape ofcoffee grounds from the unit, and it is found that coffee infusion issubstantially clearer from that obtained from conventional coiee makersof the recirculating type.

While the flow of liquid upwardly through the infusion unit isrelatively rapid it is steady and smooth, thus contributing to theeiiciency t? by manual of the infusing operation and deterring theescape of grounds. Whereas in conventional circulating type coifeemakers liquid pumped upwardly from the storage chamber is projectedagainst the top of the coffee makers, in the present case the infusedliquid merely flows gently over the top edge of unit 5l withoutimpinging on vessel lid 58.

Located in housing` 36 and separated from pump chamber 3s by cup 38 is achamber 5S in which is located rotor 6|] of an induction electric motor.Such rotor is fixed to shaft il and serves to drive rotary pump memberL32. Located externally of the bottom portion 33 of vessel te andencased in base portion 3l is electric motor stator B2. As best shown inFigs. 1 and 2 the core of such stator surrounds well 35 in the plane ofrotor 6I) contained in housing 36. Field core 63 sets up a magneticfield in the motor core which penetrates the intervening walls of well35 and housing lit to effect rotation of motor rotor and pump member 42.Rotor ed is preferably comprised of a laminated series of steel discsslotted angularly both to the axis and radius of the rotor to receivecopper inserts El. all as will be clear from Figs. l and 8. The inserts6I Yare extended inwardly almost to the center of the rotor as it hasbeen found that through such expedient the speed and power of the motoris markedly increased.

A motor controlled switch 64 is mounted on a suitable bracket in base 3ias shown in Figs. l, 2 and 6. Such switch is normally closed and causedto open by pivoted arm 65 through cam operation of push button E58. Whenarm 65 is pushed over to the dotted line position shown in Fig. 2 themotor is energized and magnetically holds arm 65 against the core aslong as the motor is operating. When the motor is deenergized spring 'i8serves to swing arm 65 outwardly and switch 64 closes.

A thermostatic switch is employed to control operation of both heatertil and the pump driv-y ing motor. As best shown in Fig. '7 thisincludes a bimetal thermostat 139 located in a water tight l casing 63in the side wall of vessel 30 so that the thermostat will be responsiveto the tempel ature of the liquid in storage chamber 32. Lo-

vcated in a second casing 'itl on the outer side of the vessel wall is aswitch arm 'il actuatable by thermostat 69 through pin 72. Swinging ofarm 1| makes and breaks contact with a second switch arm 73. Screwthreaded into casing l@ is a shaft l which can be rotated throughcontrol knob 'l5 to adjust the position of switch arm 13 the samedetermining the period of operation of the motor and heater.

By reference to the wiring diagram shown in Fig. 9 the automaticoperation of the coiee maker will be understood. Assuming that the bedof coffee grounds has been placed in infusion unit 5I and an appropriatequantity of water introduced into storage chamber i2, the coiee maker isplugged in by electric terminal 'i6 located in the base 3l and connectedto an electric power source. At this time the thermostatic switch isclosed, also the push button switch. I-Ieater 3s is immediatelyenergized, but since switch Ell short circuits the pump motor the latterremains inoperative until push button t6 is actuated. This is preferablydone immediatelyT since the water in the storage chamber heats quiterapidly. As soon as the motor is energized the pump starts operating toeect repeated separation of liquid from the storage chamber upwardlythrough the infusion unit and back to the storage chamber. After theinfusion has been completed to the strength desired as determined by thesetting of switch arm 'I3 by control knob 75, thermostatic switch opensin response to the heat of the infusion liquid in the storage chamber.Both heater 3&3 and the motor stator 52 are deenergized. The infusionmay automatically be kept warm for an indefinite period. When the liquidtends to cool slightly thermostat switch 53 will close to reenergizeheater 34 and open again when the proper temperature has again beenreached. It may be noted that closing of thermostatic switch E3 does notreenergize the pump motor since further circulation of liquid throughcoffee grounds once the proper strength has been reached is undesirable.The motor remains short-circuited by switch 5d and will not bereenergized unless and until push button 66 is again operated.

The further coffee maker as shown in Figs. l to l is generally similar'to that just described with certain differences and improvements indetailed structure. The same includes a metal coffee making vessel 3Uhaving a hollow base 8| and housing a liquid storage reservoir 82.Reduced bottom portion 33 of the vessel is sur.- rounded by an electricheating coil A central relatively small depending well 85 itself forms achamber 86 fitted with a removable specially formed cap 8l. The centralportion of the cap is provided with a series of openings constitutingports 38 through which water from storage chamber 82 enters chamber 86.At the center of the cap is a hub portion 83 in which is threaded adepending bolt S0. Located in chamber 83 and rotatable on bolt 98 is adouble rotary unit combining a rotary bladed pump member 8| andinduction motor rotor 32 which are secured to each other. Thisarrangement represents a simplification of the construction shown in theprevious embodiment. Surrounding well 35 is the core 93 of the motorstator.

Cap 8'! is formed at its underside with opposing grooves 35| and 95 ofgradually increasing depth and terminating at their depth portions inliquid outlet ports 35 and Sl. Upstanding from cap are a lpair of liquiddelivery tubes or conduits 38 communicating at their lower end withchamber 35 through ports 95 and 9i at their upper end fixed to anddischarging to the bottom of an imperforate walled coffee holdinginfusing receptacle or unit |03. In such unit the bed of coffee groundsseats on the bottom wall i0 Surrounding the outlet ends of tubes 98 and99 is a screen housing |82 screw threaded on a supporting rod |93upstanding from the center of unit lili). rhere is thus no danger of thecoffee grounds clogging tubes 38 and 59. Detachably supported on rod |33and closingr the upper end or" unit |33 is a perforate disc |04 flangedto seat on the top edge of the unit wall.

When the motor drives pump member 9| liquid from the storage chamber 82is drawn through inlet ports 83 into chamber 85 and delivered upwardlythrough tubes 88 and 89 to infusion unit me. On entering the unit theliquid flows outwardly through screen |52 and upwardly through the bedof coffee grounds, and thereafter leaves the unit through perforate disc|34 and flows downwardly back to storage chamber 82. It will be noted byreference to Fig. 12 that motor rotor pump |33, tubes 88 and 39 andinfusion unit |39 are assembled as a single unit of simple design whichcan be easily removed from the coffee maker and readily cleaned.

. metal.

The controls for the present coffee maker are generally similar to thoseemployed in the rst embodiment, but a somewhat different circuit isemployed. The pump motor is controlled by a switch IUE initiallyactuatable by a push button |33 operating through a pivoted arm |97.When the motor is energized arm |31 is magnetically held against thecore 33 of the motor rotor. A thermostatic switch |08 is housed in awater tight casing |09 in the liquid storage chamber 82. When terminals|39 located in base 8| are connected with an electric power sourceheater Sli is immediately energized. Motor switch |35 at this tim-e isin contact with switch arm I Ii) and shortcircuits the motor. As soon aspush button |06 actuates switch |35 the same is moved in contact withswitch arm resulting in energization of the motor and starting of thepump. When the circulation has continued for the required periodthermostatic switch |33 opens in response to the temperature of theliquid storage chamber, and this immediately breaks the circuit to motorS3 to deenergize the same. Arm |37 which was magnetically held by themotor core is released to break the circuit between switch |35 andswitch arm Switch I returns to contact with switch arm ||E3 whichestablishes a new circuit to the heater through a resistance unit 2. Theheater therefore does not discontinue operation as in the case of thefirst embodiment, but continues to operate at a low heat to maintain theinfusion at the required temperature. Ordinarily the low heat producedwill be adequate so that thermostatic switch |33 will not again closeuntil a new infusing operation is started.

Whereas in the two embodiments which have been so far described thecoffee maker base, heating unit and pump motor stator are permanentlyassociated with the coffee making vessel, they can constitute a separateunit. The advantage of providing a removable base is that the coffeemaking vessel is lightened to make pouring easier and facilitatecleaning. Further, the coii`ee making vessel may be constructed of glassinstead of These points are illustrated in the embodiment of theinvention shown in Figs. 16 to 22.

In the latter embodiment the coffee making vessel |23 is constituted ofglass. The bottom portion |2| thereof is made flat or slightly concave.Through use of a different form of pump motor it is unnecessary toprovide a depending well. In the central portion oil bottom |2| acut-out is provided in which is sealed a thin hanged metal disc |22 forpurposes hereafter to be described. Such disc is provided with a slightdepression serving to removably seat and center a small closed housing|23. Rotatable in such housing on bolt l is a double rotary unitcomprising a bl-aded pump member 23 and the rotor |23 of' a shaded poleinduction motor. Casing 23 forms a pump chamber i2? into which liquidfrom storage chamber |28 is delivered through a series of ports |29which are surrounded by an annular ange |33. Upstanding from housing |23are a pair of liquid circulating tubes i3! and |32 which at their upperends are connected together by a flanged disc |33. Such disc forms aportion of the bottom of an imperforate walled infusion unit |34. Tubes|3| and |32 discharge into an entrance chamber |35 in the lower portionof the unitbelow a perforate disc |353` upon which the bed of coffeegrounds are supported. Disc |35 is detachably mounted in the infusionunit by central rod |31 threaded into disc |33 mounted at the top ofunit |34 on knob |38. Fixed to the F. top of rod |31 is a secondperforate disc |39. As in the case of the previous embodiments liquiddelivered by the pump through tubes |31 and |32 flows upwardly throughinfusion unit |34 and discharges through disc |36 and thence over theedge to return to storage chamber |28.

Vessel |21! may be provided with any suitable form of cover. In thepresent instance the same is provided with a metal cover i4@ iitted witha central glass insert lill mounting knob |42 and through which a Viewof the interior of the coiee maker is afforded. Vessel l2@ may beprovided with any suitable form or" handle (not shown). The vessel maybe formed with a circumferential reduced portion |43 adapted to receivea handle supporting band, such an arrangement being preferable becauseof the glass composition oi the vessel.

Removably mounted on coffee making vessel is a base |44 of metal.Mounted in the upper portion of the base is a hollow flange |55 forminga housing 145 which is mounted on annular electric heatingfunit lll.Mounted on a transverse partition itil in base Uit is a second electricheating unit |559. Heating unit |51 is a high temperature unit employedduring the coiee making operation, while unit its is a low heat vunitemployed to maintain the infusion hot for an indenite period thereafter.As before noted the stator |25 of the pump motor is located in housing|23 above the bottom l2! oi' the coffee making vessel. The motor statorfor energizing the same is located in base unit ldd and comprises aU-shaped core |59, with its legs upturned and each surrounded by a neldcoil 55|. is suspended by partition |45 and projects downwardly througha central opening 15d therein. .es best shown in Fig. 22 a split annularring comprising sections |53 and |54 is mounted on the upper ends of thelegs of the motor stator, such ring being formed of magnetic materialand serving to establish a magnetic iield for operation of motor stator|25 and pump |25. Mounted in cutaway portions of the legs of core liebelow the ring are shading coils |55. Mounted on an annul-ar ilange 155extending inwardly from auxiliary heating unit lll@ is a thin disc |51of nonmagnetic metal which serves as a protection `for the upper end ofthe motor stator.

Supported between the legs of the motor stator is a non-magnetic casinghousing a thermostatic switch. As best shown in Fig. 18 such switchincludes an upper ld oi low expansion metal such as Invar steel havingsecured thereto a birnetallic thermostatic strip |55. Secured to the armin thermal relation with strip is a silver upwardly projecting contactelement |6|. Depending from the heat conducting contact is a guide rod|52 journalled in the lower end of casing 55%. Spring tot serves to urgemetal contact l5! upwardly so that the same will make proper thermalcontact with metal disc |22 forming the central portion of bottom |21 ofvessel |211.. Disc |22 should be ci thin non-magnetic metal so as not tointerfere with the magnetic field between the stator and rotor of thepump motor and, also, so as to respond to temperature changes of theliquid within the liquid holding receptacle.

By further reference to Fig. 18 and Fig. 1 it will be noted that theupper thermostatic switch arm |59 is adapted to float in casing |5i sothat accuracy in operation of the switch will be independent of verticaladjustment of contact pin ISI. Mounted below arm |55 is a second arm |64Such sta tor '.1

and spaced therebelow is a third arm |65. Depending from thermostaticarm |50 is a pin |56 adapted on heating to contact an insulated stud onlower arm |65 to move arm |65 away from arm |54 and break the electriccircuit normally established by thecontacts between such arms. (See Fig.18.) It will be noted by Fig. 1 that arms |59, |64 and |55 are insulatedfrom each other and secured together in spaced relation by bolt |61.Secured to bolt |51 and projecting laterally from casing |58 is a guidefinger |58 received between a pair of upstanding wings |69 secured topartition |48. This arrangement serves to keep the thermcstatic switchagainst swinging movement about rod |62 incident to upward and downwardmovement oi contact pin ll.

Hinged to the lower portion of the motor stator by pin |15 is an arm |1|of magnetically-responsive material adapted to be moved inwardly by pushbutton |12 from the full line to the dotted line position shown in Fig.17. In the latter position the inturned upper end |13 of the arm ismagnetically held against one arm of the motor stator when the latter isenergized. A. spring |14 normally tends to hold arm Ill in its leftposition. An adjustable stud |15 is mounted on arm |1| for actuating acontrol switch for the pump motor. Such switch includes normallycontacting switch arms |16 and |11 and a third switch arm |18. When arm|1| is swung in.- wardly stud |15 pressing against arm |16 moves arm |11into contact with arm |18. When the motor is deenergizedl arm |13 isswung to the left to break the circuit between arms |11 and |13. Thecircuit :between arms |16 and |11 is maintained.

By reference to the wiring diagram of Fig. 21 the automatic operation ofthe coffee maker under description will .be understood. When a source ofelectric power is connected the high heat coil |41 will be energized. Bypushing in button |12 the switch actuated -by arm |1| will be closed toenergize the pump motor. At the end of the coffee making operationthermostatc switch lB will depress arm |55 away from arm |64 to breakthe circuit to the motor and high heat coil |41. A circuit is providedthrough low heat coil |49 so that the infusion liquid is maintained hotfor an indefinite period.

For the forms of coliee maker having a metal vessel it is preferred touse stainless steel or equivalent non-corrosive metal. The exterior maybe plated with chromium, nickel or silver to enhance appearance. Themetal parts of the pump unit will preferably be plated to resistdeterioration. Plating of the infusion unit and the tubing between thepump unit and infusion unit also may be desirable in some instances,depending on the kind of metal employed therefor, but unplatedrust-resisting metals such as aluminum may be employed for such parts.

The upflow infusion unit and the pumping mechanism of the invention bothindividually and mutually contribute to a faster and more eicientinfusion of the coffee making liquid. Further, their construction isextremely simple and of light weight so as to make handling and cleaningeasy. Whereas prior power driven pump coiee makers have been extremelycumbersome and awkward to handle, the present invention provides acoffee maker of such type having all the advantages of cofee makerswhere circulation depends upon heating and the addition of smooth andhigh velocity circulation of the liquid.

The embodiments of the invention herein described are merelyillustrative, and the scope of the invention is to be: determinedaccording to the appended claims.

I claim:

l. A coiiee maker comprising a liquid holding receptacle, a coffeeholding infusion making receptacie in the upper portion of the liquidholding receptacle, liquid inlet means in the infusion makingreceptacle, a housing in the lower portion of the liquid holdingreceptacle. rotary pump means mounted in said housing for rotation abouta vertical axis including a hub and pump bladesl projecting laterallyoutward from the hub, liquid inlet means located centrally oi the top oithe pump housing over the axial area ci the pump means for delivering'liquid from the liquid holding receptacle to said pump means, liquidoutlet means in the pump housing located outwardly of said housing inletmeans, and conduit means interconnecting said pump housing outlet meansand said infusion making receptacle inlet means.

2. A coffee maker comprising a liquid holding receptacle, a coiieeholding infusion making receptacle above the liquid holding receptacle,a pair of spaced inlet ports in the infusion making receptacle, ahousing in the liquid holding receptacle, rotary pump means mounted insaid housing for rotation about a vertical axis, liquid inlet means inthe housing for delivering liquid from the liquid holding receptacle tosaid rotary pump means, a pair of liquid outlet ports in said housinglocated on opposite sides of the axis of rotation of the rotary pumpmeans, and separate conduit means interconnecting the respective housingoutlet ports with the infusion making receptacle inlet ports.

3. A coffee maker comprising a liquid holding receptacle, a coffeeholding infusion making receptacle in the upper portion of the liquidholding receptacle, liquid inlet means in the infusion makingreceptacle, a housing in the lower portion of the liquid holdingreceptacle, rotary pump means mounted for rotation about a vertical axisin said housing including a hub and pump blades projecting laterallyoutward from the hub, liquid inlet means located centrally of the top ofsaid housing over the axial area of the pump means for delivering liquidfrom the liquid holding receptacle downwardly to said pump means, liquidoutlet means located in the housing top outwardly of said housing inletmeans to which the pump means delivers upwardly, and conduit meansinterconnecting the pump housing outlet means and the infusion makingreceptacle inlet means.

4. A coffee maker comprising a liquid holding receptacle, a coffeeholding infusion making receptacle in the upper portion` of the liquidholding receptacle, a pump housing in the lower portion of the liquidholding receptacle, rotary pump means mounted in said housing forrotation about a vertical axis, liquid inlet means in the housing fordelivering liquid from the liquid holding receptacle to the central areaof said rotary pump means, a plurality of circumferentially spacedliquid outlet ports in said housing communicating with the cuter area ofsaid rotary pump means, and conduit means interconnecting the respectivehousing outlet ports with the infusion making receptacle inlet means.

5. A 'coffee maker comprising a liquid holding receptacle, a coieeholding infusion making receptacle in the upper portion of the liquidholding receptacle, liquid inlet means in the infusion makingreceptacle, a pump housing in the lower portion of the liquid holdingreceptacle, rotary pump means mounted for rotation about a vertical axisin said housing, liquid inlet means located centrally or" the top ofsaid housing for delivering liquid from the liquid holding receptacledownwardly to the central area of said pump means, an annular channel inthe upper portion of said housing surrounding said housing inlet meansand communicating with the outer area of the pump means, liquid outletmeans located in the housing top communicating with said annularchannel, and conduit means interconnecting the pump housing outlet meansand the infusion making receptacle inlet means.

6. A coffee maker comprising a liquid holding receptacle, a coiieeholding infusion making receptacle in the upper portion of the liquidholding receptacle, a hollow base supporting the relceptacle, liquidinlet means in the infusion making receptacle, housing means forming aclosed well projecting downwardly from the central area of the bottom ofthe liquid holding receptacle into the hollow base, a removable housingcover member overlying said well, rotary pump means mounted in said wellfor rotation about a vertical axis, liquid inlet means in said housingcover member for delivering liquid from the liquid holding receptacle tothe pump means, liquid outlet means in said housing cover member,conduit means interconnecting said housing cover member outlet means andthe infusion making receptacle inlet means, and power means mounted inthe base concentric with the axis or" the pump means for driving thepump means.

7. A coiiee maker comprising a liquid holding receptacle, a coieeholding infusion making receptacle above the liquid holding receptacle,liquid inlet means in the infusion making receptacle, a housingremovably mounted in the lower portion of the liquid holding receptacle,a rotary pump member rotatable about a vertical axis in Said housing,central inlet means in the housing for delivering liquid from the liquidholding receptacle to the pump member, liquid outlet means in thehousing located outwardly of said housing inlet means,V and conduitmeans interconw necting said housing outlet means and the infusionmaking receptacle inlet means.

8. A coiee maker comprising a liquid holding receptacle, a coiieeholding infusion making receptacle above the liquid holding receptacle,liquid inlet means in. the infusion making receptacle, a housing locatedin the lower portion or the liquid holding receptacle and having aremovable cover,

a vertical shaft located centrally of said housing secured to anddepending from the housing cover, a rotary pump member in the housingmounted on said shaft, liquid inlet means in the housing for delivery ofliquid from the liquid holding receptacle to said pump member, liquidoutlet means in the housing, and conduit means interconnecting saidhousing outlet means and the infusion making receptacle inlet means.

9. A coffee maker comprising a liquid holding receptacle, a coffeeholding infusion making receptacle in the upper portion of the liquidholding receptacle, liquid inlet means in the lower portion of theinfusion making receptacle, liquid outlet means for discharging liquidafter infusion from the upper portion of the infusion making receptacleback to the liquid holding receptacle, a pump housing in the liquidholding receptacle, liquid inlet means in said pump housing having ilcommunicating with the liquid holding receptacle,magnetically-responsive pump means in said housing, actuating meanslocated exteriorly of the liquid holding receptacle adapted to set up amagnetic field in said pump housing for driving v said magneticallyresponsive pump means, and `'conduit means for delivering liquid fromthe stator located below the liquid holding receptacle at the side ofthe depending housing in magnetic driving relation with said motor rotorin the' f housing, and conduit means for delivering liquid from saidhousing to the infusion making receptacle.

11. An electric coiee maker comprising a liquid holding receptacle, ahollow base supporting the liquid holding receptacle, electric heatingmeans in said base for heating said receptacle, an electric motor statorin said base underlying the central area of the receptacle, an electricmotor rotor located in the receptacle in magnetic driving relation withthe motor stator in the base, pump means in the receptacle driven by themotor rotor, a coiee holding infusion making receptacle located in theupper part of the liquid holding receptacle having a liquid inlet in itslower portion opening beneath the position of the coffee, an outlet inthe upper portion of the infusion making receptacle above the normalcoiee level for discharging liquid after infusion back to the liquidholding receptacle, liquid conduit means interconnecting the pump meanswith the infusion making receptacle inlet means for delivering liquid tobe infused from the liquid holding receptacle to the infusion makingreceptacle, and thermostatic control means controlling the operatingperiod of the pump motor means and the electric heating means.

12. A coffee maker comprising a liquid holding receptacle, a hollow basesupporting the receptacle, a coffee holding infusion making receptaclein the upper portion of the liquid holding receptacle, liquid inletmeans in the lower portion of the infusion making receptacle, liquidoutlet means in the upper portion of the infusion making receptacledelivering liquid after infusion back to the liquid holding receptacle,a closed housing in the lower portion of the liquid holding receptacleadjacent the base, rotary pump means and an electric motor rotor mountedin the hous- Yingfor rotation about a vertical axis, inlet means in thehousing for delivering liquid from the liquid holding receptacle to thepump means, conduit means interconnecting the housing with the liquidinlet means of the infusion making receptacle through which liquid isdelivered by the pump means for infusion, and an electric motor statorin the base in magnetic driving relation with the motor rotor in thehousing.

13. An electric coffee maker comprising a liquid holding receptacle, ahollow base supporting the liquid holding receptacle, electric heatingmeans 1n said base for heating said receptacle, an electric motor statorin said base, an electric motor rotor located in the receptacle inmagnetic driving relation with the motor stator in the base.,4 pump'means in the receptacle driven by the motor rotor, a coffee holdinginfusion making receptacle located in the upper part of the liquidholding receptacle having a liquid inlet in its lower portion openingbeneath the position of the coiTee, an outlet in the upper portion ofthe infusion making receptacle above the normal coffee level fordischarging liquid after infusion back to the liquid holding receptacle,and liquid conduit means interconnecting the pump means with theinfusion making receptacle inlet means for delivering liquid to beinfused from the liquid holding receptacle to the infusion makingreceptacle.

14. In a coiiee maker comprising a non-metallic liquid holdingreceptacle, an opening inthe non-metallic bottom wall of the receptacle,an insert of non-magnetic metal tted in said opening and making fluidtight engagement with the bottom wall of the receptacle, a hollow basesupporting the receptacle, magnetically-responsive pump means in thereceptacle immediately above the non-magnetic insert, actuating means inthe base adjacent the non-magnetic insert in magnetic driving relationwith the magneticallyresponsive pump means, an infusion makingreceptacle in the upper portion of the liquid holding receptacle,conduit means for circulating liquid from the pump means to the infusionmaking receptacle, heating means in the hollow base for heating thereceptacle, and thermostatic control means in the base in thermalconducting relation with the metal insert in the bottom of thereceptacle controlling the pump actuating means and the heating means.

15. A coiiee maker comprising a non-metallic liquid holding receptaclehaving an opening in the bottom wall thereof, a thin insert ofnonmagnetic metal closing said opening and making fluid tight engagementwith the bottom wall of ymeans to the coiee holder.

MAURICE H. GRAHAM.

REFERENCES CITED rhe following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 378,296 Ehrlich Feb. 21, 1888770,426 Frank Sept. 20, 1904 1,047,402 Gefter Dec. 17, 1912 1,067,206Wilkinson July 8, 1913 1,167,775 Miller Jan. 1l, 1916 1,226,005 RathmanMay 15, 1917 1,471,752 Rieckmann Oct. 23, 1923 1,719,713 Miller July 21,1929 1,789,334 Englund Jan. 20, 1931 1,972,164 Pierce Sept. 4, 19342,175,727 Graham Oct. 10, 1939 2,234,464 Calder Mar. 11, 1941 FOREIGNPATENTS Number Country Date 4,400 Great Britain 1676 51,925 Denmark July27, 1936 296,897 Italy May 30, 1932 674,259 Germany Apr. 11, 1939

